Heating device



N0V- 10, 1936. R. F. VAN sEGGERN HEATING DEVICE Filed July 29,'1955 zz 5a 52 Z4 @que INVENTOR \\/4 /Pny f' uw 55mm/v "Y WM I `ATTcJRNEw! Nov. 10, 1936. R. F. VAN SEGGERN HEATING DEVICE Filed July 29, 1933 2 Sheets-Shea*l 2 lNVENTOR /FHY F WNSEGafR/v BY MM ATTORNEY Patented Nov. 10, 1936 UNITED STATES PATENTv OFFICE HEATING DEVICE Ray F. Van Seggern, Maplewood, N. J.

Application July 29, 1933, Serial No. 682,862

12 Claims. (Cl. 122-210) My invention relates to heating devices and opening through which'the fire box has to be particularly to units adapted to be applied to inserted. The fire boxes cannot be either Wider existing furnaces or boilers to utilize heat in or higher than the ash pit opening through the ame and products of combustion passing which they are to be introduced into the furfrom a burner to the flue of the furnace. nace. For this reason it is not 'always possible 5 It is usual practice when using the gun type to provide adequate space for combustion of of oil burners for heating furnaces, or when the fuel within the re box and in no case can using other similar heating elements burning the re box extend upWardLv sufficiently to fluid fuels, to. employ a re box in the base of shield the lower portions of the water legs of the furnace into which the flame and comthe boiler. As a result that portion of the 10 bustible gases or atomized fuel are projected. water legs adjacent the bottom thereof, where- The fire box is ordinarily formed of re brick in mud and silt collect to form what is comor other refractory material which becomes monly termed a mud ring tends to become highly heated or incandescent during operation overheated and burn through.

and thus aids in the combustion of the fuel in Another and probably more important objec- 15 the furnace. tion to the water jacketed re boxes heretofore It has been suggested heretofore that a re suggested has arisen from the fact that circulabox having a water jacket be connected to the tion of steam and Water through the water boiler of the furnace for the purpose of prejacket has been poor. This has been due to the o venting overheating of the re box and the heat fact that the portion of the water jacket exthus removed from the fire box has served intending beneath the re box has been sub-- cidentally to raise the temperature of the water stantially flat and horizontal so that steam in the boiler. It is also old to construct boilers formed in the lower portion of the fire box colwith Water legs`extending down the sides of lected on the flat upper inner surface of the the furnace and beneath the bottom of the ash water compartment adjacent the bottom of the 25 pit. However, in all previous structures inre box and could not readily escape. The cluding elements in the nature of water cooled steam therefore collected and expanded forming re boxes, the fire box has either been an elean insulating layer between the re box and the ment of special construction designed and water adjacent the bottom thereof. As a readapted only for use in combination with a sult the bottom of the re box over heated and particular form of oil burner or the fire box has tended to burn through or warp, injuring or de- 30 been cast or otherwise formed as an integral stroying the fire box. Even when no steam is and permanent part of the furnace boiler. formed the heated Water in such flre boxes rises So far as I am aware, no fire box heretofore into contact with the bottom of the re box made has been adapted for application to existand forms a thick layer or skin which preing furnaces and boilers and capable of use with vents the cooler Water in the compartment from any make or style Aof gun type oil or fluid coming into contact with the heated surfaces so fuel burner. Furthermore, it has been necessary that the efficiency of the element as a heat` heretofore to make a differentsize and shape exchange device is relatively 10W. of re box for every dierent style and size of In accordance with my invention these dif- 40 furnace. This has made it necessary to conculties and objections to the structures of the struct a special fire box for every installation prior art are overcome and means provided for or in the alternative to supply a large variety of forming fire boxes of various sizes and shapes sizes and shapes of fire boxes and to fit the adapted for use with any style or size of furre box to each furnace as nearly as possible nace. The structure may be readily applied to 45 from one of a large stock of various sizes, styles either existing or new furnaces and may be and shapes of re boxes. Moreover, re boxes formed of a limited number of standard sections which are not formed integral with the boiler or parts capable of easy assembly after behave always been formed in one piece or ining introduced into the furnace. I also prostalled as avunitary structure, and it has been vide a Y structure so formed that steam and 50 diicult to introduce such fire boxes through the heated water circulate rapidly through the waash pit opening. When a water compartment ter compartment of the fire box bringing coo1 surrounds the re box the space for receiving water continuously into contact with the heated :dame as well as the size of the water jacket surfaces and removing steam and heated water is necessarily limited by the size of .the ash pit rapidly therefrom. In accordance with my in- 55 vention it is also possible `to provide re boxes of various widths and heights either wider or higher than the ash pit door, and of suicient internal dimensions to insure proper combustion of the fuel, and protection of the lower portion of the water legs of the boiler.

My invention embodies a further feature which also is new in the art in that the Water compartment of the re box may be connected to auxiliary heating means adapted to take up addtitfnal heat from the flame and products of combustion in the furnace and this heat is imparted to water passing to the boiler so that a water circuit is established which induces rapid circuation of the whole body of water in the boiler. The auxiliary heating means may take various forms and may if desired embody features and elements of the invention described in my co-pending application Serial No. 662,403, led March 23, 1933.

One of the objects of my invention is to provide a simple and inexpensive re box having a water compartment therein.

Another object of my invention is to provide elements adapted to form fLre boxes of various sizes and shapes.

A further object of my invention is to provide a fire box having a water compartment and so formed as to induce rapid circulation of steam and heated water in said compartment.

A further object of my invention is to provide a re box adapted to be applied to existing furnaces or boilers and capable of assembly within the ash pit of the furnace whereby a re box of greater width or height than the ash pit opening may be provided.

Another object of my invention is to provide a water box having a compartment adapted to receive water and having auxiliary heating elements communicating therewith and serving to utilize additional heat in the products of combustion passing to the :due of the furnace.

Other objects of my invention are to increase the absorption of heat by water circulated 'through the boiler of a furnace, to provide a simple and inexpensive heating device adapted to be applied to a wide variety of styles and sizes of furnaces, to reduce the expense of operating furnaces and to utilize heat otherwise wasted in the operation of furnaces and boilers using uid fuels.

'I'hese and other objects and features of my invention will appear from the following description thereof in which reference is made to the accompanying gures of the drawings which illustrate typical embodiments of my invention.

In the drawings:

Fig. 1 is a vertical sectional view of one form of ire box and auxiliary heating unit applied to the boiler of a furnace in accordance with my invention.

Fig. 2 is a plan view Of the form of auxiliary heating tubes and connections therefore illustrated in Fig. 1.

Fig. 3 is a detailed sectional view of one form of connection between a heating tube and the water compartment of the fire box.

Fig. 4 is a. plan of the form of :dre box shown in Fig. 1.

Fig. 5 is a transverse sectional View of the -re box taken on the line 5 5 of Fig. 4.

Fig. 6 is a longitudinal sectional view taken on the line`6-6 of Fig. 4.

Fig. 7 is a side view of the exterior of the form of re box shown in Fig. 1.

Fig. 8 is a diagrammatic end view of a. r box and alternative forzn of auxiliary heatin means.

Fig. 9 is a diagrammatic side Aview of the struc ture shown in Fig. 8.

Fig. 10 illustrates an alternative ire box con struction, and

Fig. -l1 illustrates an alternative form of a fron end section of a fire box in accordance with m invention.

In the form of my invention illustrated in Figs. 1-7 of the drawings I have shown a furnace 2 having a boiler 4, a re box 6 and a ccmbustion space 8 above the re box and beneath the crown sheet I0 of the boiler. A burner I2 for heating the furnace extends through an opening in front of the ash pit and into the front end of the re box. Flame and products of combustion are projected into the fire box and pass upwardly through the combustion space and over heating tubes I4 of an auxiliary heating device into contact with the crown sheet of the boiler. The hot gases and products of combustion then flow through openings I6 in the crown sheet into the upper pass I8 of the boiler and thence through the flue 20 to the chimney or stack. It will, of course, be understood that the particular form of furnace and boiler shown have been chosen only for purpose of illustration since the device may be applied to any other suitable type of furnace as desired.

The form of re box illustrated in Figs. 1, 4, 5, 6, and 7 is made up of a plurality of independent sections connected together to form both the :dre box and the surrounding water compartment. As shown, the re box comprises two intermediate sections 22, an end section 24 and a front section- 25. Any number of intermediate sections may be used depending upon the size of the furnace, the size of the re box and the size and style of burner used in the particular installation in question. The intermediate sections are identical in construction, each being in the form of a hollow U-shaped casting having substantially straight, vertical inner side 4 walls 26 and a curved or sloping bottom 28 joining the side walls. The water compartment 30 of each section is formed of an outer shell 32 connected to the inner side walls and bottom by webs 34 at the front and back of the Ycasting. 5 The upper ends of the inner walls and the outer shell are joined at the top by the portion 3G. Each section thus provides a water compartment presenting an upper inner face adjacent the bottom of the fire box which slopes or curves up- 55 wardly so that there is no chance for steam bubbles to collect on the lower surface thereof. Steam and heated water in the water compartment therefore, pass readily upward from the lower to the upper portion of the compartment insuring rapid circulation of the steam and water therethrough. In this way I not only avoid any possibility of steam insulating the bottom of the fire box from the water but I also induce rapid ow of hot water and steam over the upper 65 inner face of the water compartment of the re box. 'I'he water is thus kept in constant and vigorous circulation bringing cold water into contact with the heated inner face of the compartment and effecting rapid and efficient heat exchange.

The webs 34 at the front and back of the casting are provided with upper ports 38 and lowei ports 40 providing communication between the successive sections 22 and the end section 24 and the front section 25. The corresponding ports in 75 adjacent sections register andmay be connected by any suitablemeans such as pushnipples 42 engaging inwardly tapering walls of the ports 38 and 40. The sections themselves are clamped together and held in position by bolts 44 extending through bolt holes iny lugs 46 at the top of the castings and by bolts 41 extending through These bolts serve to draw the castings together and cause the push-nipples to seat firmly in the ports 38 and 40, so that a rigid water tight structure is suitable pipe compound or the like may be applied to the push nipples in the usual manner to prevent possible leaking, if desired.

The intermediate sections 22 are connected to an end section 24 in the same manner as they are connected to other intermediate sections. The end section 24, as shown in Figs. i and 4, is in the form of a hollow casting having an inner vertical face 50 lwhich is curved laterally to present a rounded surface to the flame and heated gases passing over the same. The lower portion 52 of the end face is curved or sloped inwardly and downwardly so as to direct the flames and products of combustion up over the auxiliary heating tubes I4 and against the crown sheet of the boiler.

The compartment 54 of the end section is formed by an outer shell 58 connected to the inner wallof the casting by web 58 forming a closed front for the compartment. 'Ihe web 58, like webs 34 of the intermediate sections, is provided with upper ports 62 at the top of the compartment and with lower ports 64 adjacent the bottom of the compartment at either side of the center thereof. The ports 82 and 64 provide communication between the water compartment 54 of the end section and the water compartment 3l! of an adjacent intermediate section. The inner face 50 and the outer shell 56 are connected by a portion 65 which may be tapped for connections with heating tubes i4 of an auxiliary heating device if desired.

In Fig. I have illustrated a modification of the form of intermediate and end sections described above in which central sections 66 are provided for forming fire boxes of unusual width. Thesesections may be joinedv to lateral intermediate sections 68 and to central end sections 10 by means of push-nipples or otherwise as in the construction described above. The central section is formed with a curved upper inner surface for the water compartment to insure lateral flow of steam and heated water over the surfaces thereof and therefore even when using relatively wide fire boxes embodying my invention all danger of overheating and inadequate circulation of the water through the water compartment is avoided.

Ordinarily I prefer to provide a separate front section 25 in the form of a.v casting similar to the intermediate castings 22 in transverse section but of less depth (lengthwise of the fire box). The rearwardly facing web of the front section is similar in form to the webs 34 of the intermediate sections in that it is provided with upper ports 38 and lower ports 40 for connection with an adjacent intermediate section. The front web 13 however is provided only with lower ports 14 and a centrally located cleanout port 18. The ports 14 are preferably threaded to receive the threaded end of an inlet pipe, and port 15 is formed to receive a threaded plug or other stopper. The front section is provided with lugs keep in stock has often rendered similar to the lugs 46 and 48 of the intermediate sections for securing the front section in place. If preferred, the front section may be omitted and suitable. plugs inserted into the upper ports 38 of the foremost intermediate section. Inlet pipes to supply water to the water compartment of the fire box may then be attached to each of the lower ports 40 or I may provide plug for one of the lower ports 40 and introduce watr into the water compartment through only one of the lower ports. With such an arrangement only two forms of casting are required for assembling fire boxes of various sizes, one for the intermediate sections and one for the end sections.

In Fig. 11 vI have shown an alternative form of front section 18 which is similar in its general shape to the end section 24 but is provided with an opening 88 through which the burner I2 projects. This construction provides additional surfaces for the absorption of heat from the flame and products of combustion and prevents reflected heat from heating up or injuring the front of the ash pit or the burner.

The sectional construction described above may be quickly and easily assembled by the ordinary mechanic. By connecting together any desired number of intermediate sections 22 it is possible to provide along fire box for a deep furnace or a relatively short fire box for a short or round furnace. If, for any reason, it is necessary to remove or to add sections to the fire box this may be done very readily without destroying or discarding the remaining sections of the fire box. The manufacturer and dealer then need only one size of intermediate section and one size of end section for all length of re boxes. It will, of course, be understood that the castings may be made in various widths, if desired, so that two or three sizes of intermediate and end sections will constitute the entire stock required to enable any dealer to supply a water jacketed fire box for any size or style of furnace. This flexibility of construction and assembling greatly reduces the investment required to meet the demand on manufacturers and dealers for fire boxes of this character.

Since each section of the fire box is comparatively small, it is not dflicult to introduce the sections through the ash pit opening. These are assembled in place one after the other, inside ash pit space, until a fire box of the desired size has been built up within the furnace.' The large size and difficulty encountered in placing and installing water jacketed fire boxes heretofore it impossible to use fire boxes of suillcient width to obtain the best results with a furnace or oil burner. When there is a water compartment about the fire box, the width of the inner flame receiving space is necessarily considerably less than the width of the ash pit opening through which the fire box must be inserted. In my construction, the width of the fire box may be considerably increased and may, if desired, vhave a flame receiving space that is Awider than the ash pit opening since the sections are introduced one at a time and assembled within the enlarged area of the ash pit. The height of the fire box may also be greater than that of -the ash pit opening and ordinarily is sufficient to protect the lower portions of the water legs from direct contact with the flames. In this way, I may install fire boxes having water compartments in furnaces which heretofore could not be provided with a fire box of this a suitable character because of the limited 'size of the opening through which the fire box had to be introduced. I may also provide nre boxes of suitable size and form to insure proper lcombustion. in furnaces which previously were seriously handicapped by the limited space available for the flame within the fire box, and the danger of burning out the lower portions of the water legs where mud and silt had collected.

I prefer to have the nre box lined with refractory material in each instance for the reason that such refractory lining apparently aids in the combustion of oil or other fuel. The use of refractory lining also prevents the fire box from being cooledto such an extent that the temperature of the flame is reduced suillciently to interfere with proper combustion. fractory material may be used, and it may be applied either to the inner section or to the inner face of the assembled fire box in the form of a plaster or a cement. However, I prefer to use prepared or pre-formed bricks or tiles 82 as illustrated in Figs. 1, 4 and 5 of the drawings. For this purpose, the bricks or tiles to be applied to the lower portion of the fire box are formed on their opposite edges with 84 or with tongue and groove upper edge of the fire box are preferably formed tions 88 which serve to confine the dame as it passes out of the fire box and direct the same upwardly in the center of the combustion space. That portion of the bricks extending over the upper edge of the top of the castings is provided with a recess 80 engaging a projection 92 on the inner rim of the casting to prevent the bricks from falling or tipping inward away,from the walls of the fire box. The lower edge of the bricks also is formed to prevent dislocation of the bricks 86 with respect to those extending over the bottom of the re box, and for this purpose a lower edge 94 may be inclined as shown in Fig. 5 to engage a correspondingly inclined upper edge on the adjacent bricks. With this construction, the bricks or tiles may be shipped and handled separately from the casting sections and the thickness of the refractory material will be uniform in all installations.

The bricks, tiles, cement or other refractory material used may be formed of any desired material but I prefer to use material of a refractory nature which at the same time has a relatively high heat conductivity or heattransferring capacity so that the water in passing through the compartment of the fire box will take up considerable heat and become hot or even boil. Carborundum is a typical material having the desired refractory and heat transferring properties.

While it is possible to use a fire box embodying my invention independently of the water circuit of the furnace boiler, I prefer to connect the water compartment of the fire box with the upper and lower portions of the boiler. In this way water heated in the compartment will rise upwardly to the upper portion of the boiler and cool water from the lower portion of the boiler will be drawn into the water compartment. The water circulating through the compartment of the ilre box is preferably the coolest water in the system so that the heat absorbed from the flame and products of combustion in the fire box is utilized to raise the temperature of the boiler water and increase the circulation of the curved faces of each`- with inwardly projecting porwater there through. The amount of heat taken up by the water in the system therefore is'mateportion of the water leg of the boiler and extends through the front of the ash pit or the base of the boiler and is connected with the front section 25 of the fire box. The inlet pipe 86 is threaded into the lower port 14 of the front section or may be otherwise secured to and connected with the water compartment of the nre box. If preferred, a second inlet pipe may be provided for volves considerable expense.

As shown in Fig. 1, the water compartment of the fire box may be connected with an auxiliary heating device comprising heating tubes i4 connected to the end section 24 and extending upwardly through the combustion space 8 to an upper header 98. The tubes I4 may be arranged about the arcuate upper edge of the end section described in my co-pending application referred to above.

The tubes i4 of the form of auxiliary heating device shown in assembly is greatly simplified. Q As illustrated in Fig. 2, the upper header 98 The location of the the side legs of the boiler sheet thereof.

' or new furnaces for the water jacketed fire The number and point of connection of the tubes to the fire box compartment and to the boiler may also be varied since it is only necessary that there should be no downwardly extending portions or other parts which might form steam or air traps which would prevent or interfere with the ready circulation of water through all parts of the water circuit.

In my co-pending application referred to above, I have shown and described a very efficient type of heating unit adapted to be applied to existing increasing the absorption of and products of combustion in the combustion space of the furnace. The structure described therein is formed with lower and upper headers, having heating tubes extending between the same. adapted for use in combination with the fire box of the present invention. As illustrated in Figs. 8 and 9, a heating unit embodying features of the invention described in said co-pending application is shown as employed in conjunction with box described above, in place of the auxiliary heating unit illustrated in Fig. 1. When using this type of heating unit, it is preferable to connect the lower headers IIO of the unit to each side of the water compartment for the re box. Any suitable connection, such as an elbow H2, maybe used for this purpose. I prefer to provide the connection between the water compartment of the fire box and the headers IIU at a point remote from the inlet pipe 9G which supplies water from the boiler to the 'fire box compartment. The discharge pipe |06 may then be connected to the opposite end of the upper header IIlI of the unit so that a relatively long path of travel is provided for the water circulating through the re box and auxiliary heating unit. Thus, for example, water drawn from the lower portion of the boiler will be introduced through the inlet pipe 96 at the front end of the water compartment for the fire box and will pass through various sections thereof to that section 22 to which the header IIII is connected. The water thus heated will then pass through the elbows II2 into the lower headers of the auxiliary heating unit and through the connecting tubes I4 which extend upwardly from the lower header III) to the upper header II4. The water together with any steam produced will thus be subjected to still further heating and will be discharged from the opposite end of the upper header II4 through the discharge pipe |06 and will pass into the upper portion of the boiler at a point at or adjacent the water level of the boiler.

rI'his construction provides a very large surface for absorption of heat from the flame and products of combustion in the furnace and insures rapid and vigorous circulation of the whole body of water in the boiler. The increased velocity of flow of the water over the surfaces of the boiler greatly increases the amount of heat absorbed from the hot walls of the boiler itself and for this reason the gases and products of combustion which pass out of the flue of the furnace are very much reduced in temperature and the efficiency of the furnace is greatly increased.

As shown in Fig. 9 when the furnace is comparatively deep the fire box Will not extend the full length of the furnace and the auxiliary heating unit may extend rearwardly of the iire box and have the back end thereof supported on brick I I6 or any other suitable support. With furnaces of this type the upward pass from the combusheat from the flame Such a structure is also bustion passing therethrough,

municating with tion space to the flue or upper passes of the boiler is generally located at the rear of the furnace so y that the iiame and products of combustion pass over the heating tubes to an even greater extent than if they were located directly over the fire box. The discharge pipe |06 in this construction may then extend through the pass I I8 in the upper portion of the boiler as in the construction of my co-pending application.

Although I prefer to form the fire box as described above in sections, certain features thereof and the combination of a fire box of this character with a boiler may be utilized even when the entire fire box is formed in a single unit. Furthermore, it i's not essential that the fire box sections be cast since they may also be formed of sheet steel or other material and welded or otherwise constructed if desired. 1

While I have illustrated and described certain preferred forms of my invention, it will be understood that various features thereof may be changed materially in form and construction without departing from the spirit and scope of mi invention.

I claim:

1. A unit adapted to be applied to existing boilers fired by oil burners to increase the absorption of heat from the flame and products of comcomprising a fire box having a compartment adapted to receive water extending about the bottom and sides of the fire box, the upper inner surface of which compartment presents an inclined face, heating tubes extending transversely of the path of flame and products of combustion passing from said fire box and into contact with said boiler, means connecting the lower end of the heating tubes to the compartment in said re box, and means connecting the upper ends of said heating tubes to the upper portion of said boiler.

2. A unit adapted to be applied to existing bollers fired by oil burners to increase the absorption of heat from the flame and products of combustion passing therethrough, comprising a member having a compartment adapted to receive water, heating tubes positioned above said member and extending transversely of said iiame and products of combustion, a lower header to which the lower ends of said heating tubes are connected comthe compartment in said member, an upper header to which the upper ends of said heating tubes are connected, a connection between the lower portion of said boiler and the compartment in said re box and a connection between the upper header and the upper portion of the boiler connected to a point on said boiler which is not exposed to heat from said oil burner.

3. The combination comprising a boiler having a combustion chamber, an oil burner for heating said boiler discharging flame into said combustion chamber, a firebox adapted to be applied to the boiler extending about the sides, bottom and end of the combustion chamber in position to be heated by flame from saidvoil burner, said fire box being formed of a plurality of hollow sections each having a water compartment thereconnecting the water compartment of another section to the upper portion of the boiler.

4. The combination comprising a boiler having a combustion chamber, a fire box having a water compartment therein located in said combustion chamber, a plurality of interchangeable heating tubes of substantially the same length and form communicated at their lower ends with said ilre box and a header to which the upper ends of said heating tubes are connected communicating with said boiler.

5. In combination with a fire box having a compartment for receiving water and formed with a curved portion, a plurality of heating tubes connected at their lower ends to the'curved portion of said flre box and a header to which the upper ends oi said heating tubes are connected, said header having a portion thereof similar in configuration to the curvedportion of said re box.

6. The combination comprising a boiler hav-A ing a combustion space therein, an oil burner for heating said boiler, a member having a water receiving compartment therein which member is spaced from the oil burner andl located in part at least below the same, a connection from the lower part of the boiler to said compartment, heating tubes connected to the upper portion of said member and extending transversely of the path of ilow ofilame and products of combustion passing from the oil burner over the surface of the boiler and means connecting said heating tubes to the upper portion'of the boiler, whereby a circuit is provided for the ow of water from the lower portion of the boiler through the compartment in said member and thence through the heating tubes to the upper portion of the boiler.

7. In combination with a boiler having an ash pit door opening and a combustion chamber extending above said opening and provided with a fire door opening, an oil burner from which ame and products of combustion pass upwardly through said chamber, a supplemental water heating device having a hollow water receiving portion thereof extending upwardly at one side passing from said oil burner over the boiler surfaces and means connecting said supplemental heating device to the boiler to provide for the circulation of boiler water therethrough, said of the supplemental heating device through the fire door opening to the upper portion of the boiler.

8. In combination with a boiler having a combustion chamber, an oil burner located at one side of the boiler adjacent the bottom thereof discombustion issuing from said oil burner and passing upwardly over the boiler surfaces.

9. The combination comprising a boiler having a combustion chamber, an oil burner for heating said boiler extending into the front of the boiler adjacent the bottom thereof, a. member having a water receiving compartment therein located in the combustion chamber adjacent the rear of the boiler and opposite the oil burner, a connection from the lower part of the boiler to said: compartment, spaced tubular heating ele` ments communicating with said member and extending upwardly and forwardly therefrom in the combustion chamber and in the path of flow of ame and products of combustion passing from the oil burner. over the surface of the boiler and means connecting the upper ends of said tubular elements to the upper portion of the boiler, whereby a circuit is provided for the ilow of water from the lower portion of the boiler through the compartment in said member and thence through the tubular elements to the upper portion of the boiler.

l0. In combination with a boiler having a combustion chamber and water legs extending downwardly about the same, an unjacketed portion below the water legs of the boiler and an unjacketed portion above the bottom of the water legs, an oil burner discharging flame and products of combustion into the combustion chamber so that they pass upwardly therethrough, a supplemental heating device located within the combustion chamber comprising a hollow body through which boiler water is circulated having a portion thereof extending upwardly at the rear of the combustion chamber above the bottom of the water legs and a communicating water receiving portion thereof extending forwardly therefrom over flame and products of combustion passing upwardly through the combustion chamber, and connections between said body and the boiler completing a circuit for the ow of boiler water therethrough including a conduit communicating with the lower portion of said body and passing from the lower portion of the boiler through said unjacketed portion thereof below the water legs and a conduit extending from the upper portion of said body through said unjacketed portion of the boiler above the bottom of the water legs to the upper portion of the boiler.

11. In combination with a boiler of the vertical flue type having a combustion chamber through which gases pass substantially vertically and water legs extending downwardly about the same, an unjacketed portion below the water legs of the boiler and an unjacketed portion above the bottom of the water legs, an oil burner discharging llame and products of combustion into the comwater legs and extending substantially horizontally in said chamber so that flame passing substantially vertically through the the boiler above the bottom of the water legs to the upper portion of the boiler.

12. In combination with a boiler having a combustion chamber, an oil burner located at one side of the boiler adjacent the bottom thereof discharging flame and 'products of combustion into said combustion chamber to heat the boiler surfaces and a supplemental water heating device provided with connections extending from said device to the exterior of the boiler and communicating with the upper and lower portions thereof to provide a path for the circulation of boiler water through said device, said device being located in the combustion chamber and formed with a hollow Water-receiving portion positioned on the side of the combustion chamber opposite said oil burner and with a communicating hollow water receiving portion extending substantially horizontally over flame and products of combustion issuing from said oil burner and passing upwardly through the combustion chamber.

RAY F. VAN SEGGERN. 

